Furnace



(No Mddel.) 2 Sheets-Sheet 1.

E. W. TUCKER. MEEURNAOE. No. 363,264. Patented May 17, 1887.

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(No Model.) 2 Sheets-Sheet 2.

E. W. TUCKER.

. FURNACE. No. 363,264. Patented May 17, 1887.

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UNIT D STATES PATENT Oriana,

EDYVIN WVARREN TUCKER, OF HONOLULU, HAVAII.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 363,264, dated May 1'7, 188?. Application filed October 7, 1886. Serial No. 215,635. (No model.) Patented in Hawaii JuneD, 1886, No. 36.

To all whom it may concern:

Be it known that I, EDWIN WARREN TUCK- ER, of Honolulu, Oahu, Hawaiian Islands, have invented an Improvement in Furnaces; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to that class of furnaces in which ahollow or chambered bridge-wall is employed for the introduction of hot air into the combustion-chamber of the furnace; and my invention consists in the novel and particular details of construction hereinafter described and relating to the bridge-wall, the means for securing and adjusting it within the furnace, the manner of mounting and means for operating the damper controlling its airentrance apertures, the shield protecting said damper, the wall of bricks or other material protecting the front or face of the bridge-wall from contact with the slice-bars and fire-hoes,

and to other parts thereof.

The object of my invention is to provide a hollow or chambered bridge-wall for the introduction of hot air to the combustionchamber, of such a construction as is necessary to its completeand perfect adj ustment and adaptation to marine boilers, or to other boilers having internal furnaces, so that the required strength may be produced conjointly with such economy of room in the combustion-chamber as will permit ready access to it and will leave the utmost practicable space for the flame to come in contact with the water-spaces of the boiler.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure 1 is a vertical section of the boiler and furnace, showing the bridge-wall. Fig. 2 is a vertical crossseetion of the upper or removable portion or top of the bridge-wall. Fig. 3 is a front view of same, showing the sections in which the top portion may be made. Fig. 4 is a vertical cross-section of the lower portion of the bridge-wall, showing the mounting of the damper and the rod for operating it. Fig. 5 is a front elevation of Fig. 4.

A is the furnace, having combustion-chamber B.

O is the bridge-wall, made hollow or chembered, as shown. It consists of two main portions orcastings, which are here designated by c and c, the former being the upper portion or top, and readily separable from the latter, which is the lower or permanent portion, remaining in place during the life of the boiler or any lesser period, but removable at will, and receiving any number of tops as they may be successively needed. The removable top 0, as shown in Fig. 2, is an angled casting, consisting of a front plate and a top plate, through the latter of which are made any number of apertures or slots, 0', which are distributed over the entire surface of the plate for the equal and perfect distribution of the air through the metal, whereby it is prevented from being burned out by the intense heat which surrounds it or the concentration of heat at any point within the chamber, These apertures or slots are made with a divergent downward bevel, in order to prevent them from becoming clogged.

The top 0 need not necessarily be a single casting, for it may be made in two sections, Fig. 3,0r more, as the size of the furnace requires, so as to admit of its being more easily handled or removed, when occasion requires, for cleaning or repairing the back tube-sheets andcombustion-chamber. Thelowerportion, c, of the bridge-wall is a single hollow casting, having, as shown in Fig. 4, the shape in cross-section of an inverted right-angled triangle, of which the hypotenuse is formed by the back plate, an upper back plate, 0, and a leg-rim, 0 forming also part of said casting. Through the top plate of said casting are made large openings or slots 0 Through its front plate are made the air-entrance slots 0", and in its back plate is made the hand-hole c.

In some cases, if deemed desirable, the back plate of said casting may be formed separate from the other parts and subsequently bolted on. Now, by reference to Fig. 1 it will be seen that the lower casting, c, is below the level of the grate-bars and supports their inner ends. It acts as a chair or seat for the upper casting, c, which rests uponthe top plate of the lower casting by its own front plate, while the back of its top plate rests against the upperback plate, 0 of said lower casting. The upper casting is secured in position by bolts D, pass- ICO ing through the upper back plate, 0 and the front plate of the upper casting, as shown.

. The two castings thus form the complete bridge-wall, their hollows or chambers being practically one, by reason of the slots or openings in the top plate of the lower casting, the presence of which plate gives strength to the construction. The lower casting is secured within the combustion-chamber in any suitable manner, and it'stands on the lower wall of the furnace upon its leg or bottom rim, 0*. This leg or rim, as is shown, covers but a limited space, so that when observed in connection with the inclined back plate of the lower casting it will be seen that the least practicable area of the water-space of the boiler is covered, thereby enabling the flames to come in contactwith the walls of. said space over the greatest possible area. The lower casting as thus constructed is practically indestructible by heat, and will last the life of the boiler; but the upper casting, being more exposed, is more liable to have a shorter life. When desirable or necessary, it is easily removed by loosening the bolts D, which secure it, so that a new one may be substituted; but this is not the only advantage in having the upper casting readily removable, for by taking it out much more space or room is afforded for cleaning or repairing the combustion-chamber and the bridge-wall itself.

On the front plate of the lower casting is cast a ledge or rib, c", with a backwardlybeveled upper surface. In this rib is mounted by its correspondingly-beveled base the transversely-sliding damper E, made with-slots e for coinciding with the air-entrance apertures c of the'lower casting, in order to open the communication, or, by moving out of line therewith, to close them, after the manner of ordinary dampers. The upper end or top of the damper is not connected at all with the casting, so that it can expand and contract without in any way restraining its motion or impeding its operation.

The mounting of the damper in the beveled support or rib c keeps it up snugly to the face of the casting, with the assistance of the rod by which it is operated and the bolt by which it is guided. These are as follows: Referring to Fig. 5, it will be seen that an elongated widened slot, d,'is made in one end, which fits over a bolt, d, passing into the casting c. A rod, F, Fig. 1, passes from near the ash-pit door G back through the space under the grate-bars of the furnace, and is pivoted or journaled, Fig. 4, in the front plate of the lower casting of the bridge-wall. Connected with this rod is a crank, f, having a pin, f.

The damperE is provided with slots (1 and (2 in which the rod F and the crank-pin f loosely play, as shown in Fig. 5. By turning the rod F the damper E is moved sidewise, and this movement, by reason of the large guide-slots made in it, is in a straight line,so that the damper operates accurately and easily.

On the front plate of the lower casting of the bridge-wall is formed a projecting piece or shield, H, directly over the damper. This is forjthe purpose of keeping all the ashes and pieces of fine coal from falling on top of and into the damper, which would have a tendency to clog its operation and impair or destroy the volume and regularity of the passage of air into thebridge-wall until such times as the bricks, I, before it, which rest upon the top plate of the lower casting. These bricks are not for the purpose of protecting the bridgewall from burning out, as it needs no such protection, for the constantcurrent of air through I it prevents this.

The general operation of the introduction of the air is sufficiently illustrated by the arrows, and needs no further description.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A hollow or chambered bridge-wall for furnaces, consisting of a lower fixed portion below the level of the grate-bars and having an upper back plate, 0 in combination with a removable upper portion having a front plate and aperforated top plate resting against said back plate, substantially as herein described.

2. The hollow or chambered bridge-wall 0, consisting of the angled casting or upper portion, 0, with a perforated top plate, and the lower casting or portion, 0, with an upper back plate, a slotted or open top plate, and an tion, 0, with a perforated top plate, the lower casting or portion, 0, having an upper back plate, a slotted top plate, and an apertured front plate, and the bolts D, by which the upper casting is secured to the lower and is adapted to be readily removed therefrom, substantially as herein described.

4.. The combination of the hollow or chambered bridge-wall 0, comprising an upper removable casting, 0, having a front plate, a top plate provided with diverging apertures, a lower casting, 0, below the level of the gratebars, and the wall of bricks protecting the front plate of the upper casting from the slicebars and fire-hoes, substantially as herein described.

5. The upper casting, a, havingafront plate and perforated top plate, in combination with the lower casting, 0', having a sloping back and a leg for rim, 0, upon which it stands, sub'--- stantially as herein described.

6. The lower casting, a, of the hollow or chambered bridge-wall (3, having the apertures c in its front plate and the bevel-faced ribor ledge 0 under said apertures, in combination with the laterally-moving slotted damper E,

controlling the apertures, having a beveled base mounted 011 the rib or ledge and its top free, substantially as herein described.

7. The lower casting, a, of the hollow or V 5 chambered bridge-wall 0, having the apertures 8. The combination of the lower casting, 0, having the shield-flange H, flange c and ap- 5 ertures c, the damper E, and an upper por tion, 0, bolted to the lower portion, substantially as herein described.

In witness whereof I have hereunto set my I hand.

EDWIN WARREN TUCKER.

Witnesses:

G. D. COLE, J H. BLooD. 

